Plastic casing for air exhauster



15in-195 SQ y June 13, 1961 l. 1. soLzMAN 2,987,983

s PLASTIC cAsING FOR AIR ExHAUsTER Filed oct. 28, 1958 I s sheets-sheet 1 1 25 '2 7e se 8 '6 INVENTOR |9 *ISEL LSOLZMAN ATTORNEYS June 13, 1961 l. l. soLZMAN PLASTIC CASING FOR AIR EXHAUSTER 5 Sheets-Sheet 2 Filed Oct. 28, 1958 INVENTOR ISEL I. SOLZMAN V-l BY M@ June 13, 1961 l. i. soLzMAN PLASTIC CASING FOR AIR EXHAUSTER 3 Sheets-Sheei'l 5 Filed Oct. 2.8, 1958 INVENTOR lSEL [.SOLZMAN /waq ATTORNEYS,

United States 2,937,983 Patented .lime 13, 1961 ine 2,987,983 PLASTIC CASING FOR AIR EXHAUSTER Isel I. Solzman, The Gallaher Co., 4108 Dodge St., Omaha, Nebr. Filed Oct. 28, 1958, Ser. No. 770,073 4 Claims. (Cl. 98-43) The present invention relates to a new and improved power roof exhauster such as disclosed in my Patents Nos. 2,526,290 dated October 17, 1950 and 2,777,382 dated January 15, 1957.

An important object is to form the casing for the motor and fan of the exhauster, of sound-absorbing non-resonant material, such as Fiberglas and the like, so that the casing has high dimensional stability that is structurally equal to steel and a greater impact strength than aluminum, copper o1' steel. Additionally, the Fiberglas is not detrimentally affected by salt spray, moisture, gases, acids, greases and the like. Due to the fact that the color of the casing is saturated into the material, the casing need not be painted and will last a lifetime without additional maintenance expense. The reenforced Fiberglas casing also has a special non-hygroscopic hardened surface nish as well as being completely weather-proof and is protected against corrosion so as to meet the exacting demands of the worst working conditions.

A further object consists in separating the Fiberglas casing of the air exhauster into an upper motor housing and a lower fan housing. The fan housing includes a lower curved hood and a spaced upper curved hood. The lower hood may have connected to it a depending Venturi air inlet or tubular member by an outwardly and laterally annular shoulder, provided with circumferentially spaced openings, for allowing liquid condensation within the casing to escape therefrom. The upper and lower hoods are shaped to form a smooth walled chamber in which is mounted the fan for circulating air from a building into and through the exhauster, and are spaced from each other to provide an annular peripheral and downwardly disposed discharge air passage. The upper hood may include a curved or substantially dome-shaped cover which may -be spaced outwardly from the vertical flange of a flat horizontal member to which it is connected at spaced points so as to permit the free flow of outside air into the motor casing formed by the at member and its connection with the cover. The iiat member rests on the top of the upper hood and is connected to the lower edge of the cover at circumferentially spaced points. The sound-absorbing material which forms the cover, insulates the motor to insure continuous cool operation of the same. The inner wall or surface of the cover which encloses the motor is made with a porous and rough finish so as to serve as a sound absorbent for reducing the noise of the motor and also provides a rough or irregular surface which will prevent noise from being reflected into the building in which the exhauster is installed. The inner confronting surfaces of the upper and lower hoods, as well as the venturi inlet, are smooth as glass so as to reduce friction and turbulence and also facilitates the free flow of air through the exhauster. Additionally, the motor is out of this air stream and an air seal-off is provided which forms a curtain of fresh air under negative pressure around the motor shaft.

A further object comprehends the provision of a power roof exhauster or the like, including a polygonal-shaped fan housing, on which is mounted the motor, and enclosing the motor in a removable housing or cover. The housing for the fan and motor are formed or may be coated with any suitable sound-absorbing non-resonant material, such as Fiberglas or the like. The inner wall of the motor housing is provided with a rough and porous surface or finish so as to absorb motor noise and also to destroy any tendency to focus sound back through the exhauster or equipment. The inner wall surface of the fan housing is very smooth so as to reduce turbulence and skin friction which heretofore has been an objectionable feature when treating metal surfaces due to the irregularities caused by spinning metals.

Other objects and advantages of the invention will become apparent from the following description when taken in conjunction with the accompanying claims and drawings.

Referring to the drawings, in which are shown several preferred embodiments of the invention:

FIG. 1 is a perspective view of a power roof exhauster, constructed in accordance with the present invention;

FIG. 2 is a vertical sectional view of FIG. l;

FIG. 3 is a sectional view taken substantially along the line 3 3 of FIG. 2 and looking in the direction of the arrows;

FIG. 4 is a sectional view taken substantially along the line 4-4 of FIG. 2, looking in the direction of the arrows;

FIG. 5 is a side view, with parts in section, of a modified form of the invention;

FIG. 6 is a perspective view of a further modification;

FIG. 7 is a perspective view of the form of the invention shown in FIG. 6, with the motor housing or cover in its opened position and parts in section for clearness of illustration;

FIG. 8 is a detailed section on the line 8--8 of FIG. 6; and

FIG. 9 is an end view of FIG. 6 showing the side thereof formed with a pair of louver openings or vents.

Referring to FIGURES 1 and 2 of the drawings, 10 generally indicates the casing of a power roof exhauster formed of a suitable sound-absorbent non-resonant plastic material, such as Fiberglas 0r the like. The Fiberglas casing 10 is separated into an upper motor housing or cover 11 and a lower fan housing 12. The fan housing 12 includes a lower plastic hood 13 (FIG. 2) and an upper plastic hood 14 spaced from the lower hood. The lower hood '13 has an intermediate curved portoin 9 which extends upwardly and then downwardly to form a depending annular end flange 15. The lower or opposite end of the hood 13 merges into an annular horizontal portion or shoulder 16 which, in turn, terminates in a depending ared venturi air inlet or tubular sleeve 17, shaped to form at its lower end the horizontal base 18 having the depending annular vertical portion 19 which registers with an opening 20 in the roof 21 of a building or the like, so as to be permanently installed in a fixed position at the desired point where the equipment is to be used. Thus, it will be seen that the lower hood 13, venturi inlet 17 and supporting base 18 are all made of one-piece of sound-absorbent material, such as Fiberglas or the like. The shoulder 16 adjacent the juncture of the venturi inlet 17 therewith Vis preferably formed with circumferentially spaced openings 8 for allowing condensation of liquid that may collect or form within the casing, to escape outwardly from the exhauster 10. The upper end of the tubular portion or sleeve 17 projects above the horizontal portion 16, as at 17', so as to provide a trap for collecting the liquid condensation formed within the fan housing and facilitate its withdrawal through the openings 8.

The lower hood 13 is spaced from the upper hood 14 by any suitable means, such as the circumferentially spaced sleeves or brace members 22 connected in any suitable manner to the hoods, such as by the screws 23. Thus, it will be seen that the lower hood 13 coacts with the upper hood 14 to provide a chamber 24 directly above the venturi inlet 17 and in which is positioned any suitable type of fan, such as a squirrel cage blower wheel or turbine fan '25.

The plastic upper hood 14 has a fiat annular horizontal portion 26 provided with a central opening 27 that closes the top of the chamber 24, and is also formed with an annular downwardly iiared outer peripheral ange 28 which is spaced from the outer end 15 of the lower hood so as to form a downwardly tapered annular air discharge passage 29 that extends completely around the fan chamber 24 so as to direct the air from the chamber 24 outwardly and downwardly therefrom. The confronting inner surfaces of the lower hood 13 and the upper hood 14 are smooth so as to reduce frictional resistance of the air passing through the fan housing.

The lower open end 30 of the dome-shape or curved cover 11 is spaced from the flat portion 26 of the hood 14, as at 31, so as to allow outside air to be introduced into the cover. Extending upwardly into the space 31 is a cylindrical member or sleeve 32 preferably made of the same plastic material as the casing and which may have its inner surface 33 either rough or smooth. The member 32 is connected to the fiat portion 26 of the hood 14 in any suitable manner, such as by the circumferentially spaced L-shape brackets 34 and the bolts or screws 34. The member 32 is also rigidly secured to the inside of the cover 11 by suitable fastening means, such as the bolts 35 and nuts 35'. The fiat horizontal potrion 26 of the hood 14 is thicker than the remaining portion of the hood so as to provide a strongr supporting surface. Extending through the opening 27 of the liat portion 26 is a motor shaft 36 of the motor 37. The motor 37 is enclosed within the cover 11 and rests on the fiat portion 26 of the hood 14, so as to be secured thereto by suitable fastening means as at 38.

The motor housing or cover 11 is preferably of hemispherical shape and has the inner surface thereof formed with a porous and rough finish 11' so as to serve as a sound absorbent for the motor noise and also insulates the motor to insure cool operation thereof. In other words, the rough or irregular surface 11 not only effectively impedes the transmission of heat but also absorbs and deadens sound waves. The motor 37 is directly connected through the vertical shaft 36 to the squirrel cage blower wheel or fan 25. Additionally, the motor is rigidly mounted in the casing 10 and is isolated against vibration. The casing 10 is not only waterproof but is so shaped as to be capable of converting fa portion of the high Velocity air at the blade exit passage 29 to static pressure.

In operation, the air in the building is drawn upwardly through the opening in the roof 21 through the venturi inlet 17 and is forced outwardly from the fau casing 24 through the smooth surface passage 29 which, as shown, is in the shape of a double overhanging umbrella outlet. At the same time, the outside air introduced into the motor housing 11 through the segmental spaces 8 (FIG. 3), serves to cool the motor 37 and then is discharged through the opening 27 into the fan casing 24 so as to mix with the air coming through the venturi inlet 17 prior to the discharge thereof through the downwardly inclined passage 29. Due to the thermal conductivity of the rough surface of the Fiberglas in the housing 11, the motor in the housing 11 will run much cooler and its life materially prolonged. Additionally, the Fiberglas inside the housing 11 serves to deaden the hum and objectionable sounds caused by the rotary elements during the operation of the exhauster. As the confronting inner surfaces of the lower hood 13 and upper hood 14 are very smooth, it serves to eliminate skin friction and gives a less turbulent flow to the air as .it is discharged from the passage 29.

Thus, it will be seen that the plastic or Fiberglas casing for housing the fan and motor 37 of the exhauster may be readily installed at a minimum expenditure of time, effort and cost, and can easily be packed for shipping. Moreover, the parts are constructed and arranged so as to insure high efficiency and the exhauster is capable of handling static pressures to 4". The rnotor 37 is positioned above the fan housing 24 so as to oe out of the air stream and during operation of the fan 25, a curtain of fresh air is formed under negative pressure around the motor shaft 36. The power roof exhauster 10 may be shipped completely assembled and, due to the plastic formation of the casing, the fan 25 and motor 37 are protected by a weather-proof Fiberglas casing capable of withstanding the severe uses to which devices of this character are normally subjected.

The modified form of the invention shown in FIG. 5 is substantially similar to that previously described, with the exception that the parts constituting the casing for the fan and motor, instead of being exclusively formed of sound-absorbent material, such as Fiberglas or the like, may be constructed of a suitable light metal, to the inner and outer surfaces of which are applied in any suitable manner, a sound-absorbing non-resonant material, such as Fiberglas or the like. In other words, the upper motor housing 11, fan housing 12, venturi tubular air inlet 17, base 18, and member 30 and its annular ange 31, are all initially formed of metal 3S' to which is suitably applied the sound-absorbing non-resonant material so as to cover, as at 39, the inner surface of each of the metal parts and as at 443 the outer surface thereof, in order to provide sound-absorbing means covering the metal surfaces. The inner coating or layer of Fiberglas 39 on the curved housing 11 is made with a porous and rough finish so as to serve as a sound absorbent for the motor noise and also insulates the motor 37 to insure cool operation thereof. The fan 25 in the chamber 24 is operatively connected to the motor 37 through the drive shaft 36 in the manner as previously described. The confronting inner. surfaces of the lower hood 13 and the upper hood 14 are smooth so as to permit the free discharge of the air through the passage 29 during the operation of the exhauster. The spacing members 22 are shown re-enforced by spaced suitable retaining bolts 41 that extend through suitable aligned openings in the base 18, lower housing 12, and upper housing 14, so as to be suitably connected, as at 42, to the inner wall of the spacer sleeves 22 and thus provide additional means for supporting the parts of the casing in their operative position. Each of the bolts bolts 4l is enclosed in a tubular sleeve made of the same nonabsorbent material as the plastic applied to the metal surfaces of the exhauster. Preferably, both the inner and outer surfaces of the parts of the metal casing have the sound-absorbing material applied thereto so as to provide weather-proofing means that is unaffected by salt spray, moisture, gases, acids, greases and the like and which additionally, due to the rough surface of the inner wall of the housing 11, provides non-conduction of heat and sound insulating means for the motor 37. The lower hood 13 adjacent the juncture of the venturi inlet 17 therewith is formed with circumferentially spaced openings 43 so as to allow condensation of liquid that may collect in the lower housing 28, to escape outwardly of the exhauster. Otherwise, this modified form of the invention is substantially similar in operation to the form previously described.

In the modified form of the invention shown in FIG- URES 6 and 7, the air exhauster casing is indicated generally by the numeral 45 and may include a lower fan housing 46 of any suitable polygonal shape and which, for the purpose of illustration, is disclosed as substantially rectangular coniiguration. A motor housing or cover 47 is removably mounted on top of the fan housing 46 and may be hinged thereto, as at 48. The parts of the casing are formed of suitable sound-absorbent non-resonant plastic, such as Fiberglas or the like, and the fan genaues;

housing is of such' size and shape as to fit over an open ing in the roof of a building to which the exhauster is tov be installed so as to be permanently secured thereto. 'Ihe closed at top 49 of the fan housing 46 has a central opening 50 through which extends an operating shaft 51 that is suitably secured to a fan 52 rotatably mounted within the housing 46. A supporting bracket 53 has a vertical end wall 54 and confronting side walls 55 which may be of triangular shape and provided, at their lower ends, with flanges 56 that rest on the top 49 of the housing 46, so as to be secured thereto by the fastening means 57 (FIG. 7). Vertically spaced bearing blocks SB are connected, as at 59, to the vertical end wall 54 and are arranged to receive the rotatable shaft 51 which, at its upper end 60, extends beyond the wall 54 and has xed thereto a pulley 61 over which passes an endless belt 62 that engages the pulley 63 on the drive shaft 64 of the motor 65. As shown, the motor 65 is secured to the outer wall 54 of the bracket 53. Thus, it will be seen that upon operation of the motor, the shaft 51 and fan 52 will be rotated so as to force outside air into the fan housing 46.-

The motor housing 47 is preferably shaped, as shown in FIG. 6, and has the inner wall thereof lined with rough porous non-absorbent plastic material, such as Fiberglas or the like, as at 66 (FIG. 7), so as to serve as a sound absorbent for reducing the noise of the motor and isolate vibrations which -might attempt to pass through the exhauster. A substantially rectangular frame 617 may be secured to the top 49 of the fan housing 46 and extends upwardly therefrom to form a shoulder portion 68 and an upwardly projecting rib 69 arranged to extend into the cover 47 when the parts are moved to their closed position, so as to insure a tight sealing engagement between the fan housing and the motor housing. Outside air is introduced into the motor housing 47 through the louver openings or vents 7i) (FIG. 8) preferably formed in the confronting sides 71 of the cover 47 so as to allow atmospheric air to be introduced into the housing 47 to cool the motor 65. Extending downwardly and outwardly from the top and side walls of the vents 70 are the inclined flanges 72 for guiding the outside air upwardly into the motor housing 47. While the inner surface of the fan housing is provided with a surface as smooth as glass, so as to facilitate llow of air through the exhauster, the inner walls or surfaces of the cover 47 are rough and porous so as to form irregular sound-absorbing and heat-insulating means for the motor. In FIG. 9 the opposite sides of the motor housing 47 are shown provided with a pair of louver openings 73.

In all forms of the invention the plastic casing is of suiicient strength and durability as to be firmly secured to a roof or the like, and to rigidly support the motor and its associated parts without in any way detracting from the ecient operation of the air exhauster. Moreover, all the air-handling surfaces are extremely smooth due to the molding process employed in forming the fan and motor housings. Consequently, none of the irregularities are present, such as caused by spinning metals.

This novel arrangement results in a lack of turbulence and less skin friction than in metal spinnings. As a result, less noise is generated during the operation of the exhauster, while the rough and porous inner wall of the motor housing acts to absorb motor noise at its point of generation. The rough surface further serves to destroy any tendency to focus sound back through the exhauster or equipment. While the plastic non-resonant casing is shown associated with an air exhauster, it will be manifest that it may, with equal eiiiciency, be utilized to provide a cover or hood for absorbing noises and vibrations of various kinds and is so constructed and arranged as to be installed at a minimum expenditure of time, effort and cost.

tural strength as to equal that of steel and has au impact strength in excess of steel, aluminum or copper, so as to provide a power roof exhauster that may also be used eiciently to absorb noises developed with various types of machines and which is so unalected by salt spray, moisture, gases, and greases. Further, the sound-absorbing non-resonant material serves to insulate the motor so as to insure continuous, cool operation.

It will be understood that the several forms of the invention shown are merely illustrative and that such changes may be made to the air exhauster as come within the purview of the following claims:

I claim:

1. An air exhauster of the class described including a casing comprising sound-absorbing non-resonant fiber reinforced material, said casing being separated into an upper motor housing and a lower fan housing, said fan housing having a depending venturi air inlet portion connected at its upper enl to the fan housing by an annular outwardly extending shoulder, said venturi inlet extending upwardly above said shoulder to form a liquid trap, said shoulder being provided with ciroumferentially spaced openings for allowing liquid condensation formed in the casing to escape therefrom, said fan housing including a lower curved hood and an upper hood spaced from the lower hood, said lower hood having a curved intermediate portion extending upwardly and outwardly and then downwardly to form a depending end flange, said lower hood having its opposite end merging into said annular shoulder, said upper hood having a fiat circular portion provided with a downwardly and outwardly extending peripheral ange spaced from the flange on the lower hood to form a discharge passage therebetween, means for spacing the lower hood from the upper hood, said motor housing being of substantially hernispherical shape and having an inner wall surface of fiber-reinforced material which is porous, rough and non-reilecting to provide sound-absorbing means for reducing the motor noise and said upper and lower hoods and said inlet having smooth inner surfaces of ber-reenforced material to facilitate the discharge of the air therethrough.

2. An air exhauster of the class described including a casing comprising sound-absorbing, non-resonant fiberreenforced material, said casing being separated into an upper motor housing having a motor therein and a lower fan housing having a fan therein operable by said motor, said fan housing having a depending venturi air inlet portion connected at its upper end to the fan housing by an annular outwardly extending shoulder, said fan housing comprising a lower curved hood and an upper hood spaced from the lower hood, said lower hood having a curved intermediate portion extending upwardly and outwardly and then downwardly to form a depending end flange, said lower hood having its opposite end joined to said annular shoulder, said upper hood having a at circular portion provided with a downwardly and outwardly extending peripheral ange spaced from the ange on the lower hood to form a discharge passage therebetween, means for spacing the lower hood from the upper hood, said motor housing including means for absorbing sound and reducing the motor noise, said last named means comprising a porous and rough non-refleeting inner wall surface of fiber reenforced material adjacent said motor, the discharge passage formed by said upper and lower hoods having smooth surfaces of ber-reenforced material to facilitate the discharge of air therethrough.

3. An air exhauster of the class described including a casing comprising sound-absorbing non-resonant Fiberglas material, said casing being separated into an upper motor housing having a motor therein and a lower fan housing having a fan therein operable by said motor, said fan housing having a depending venturi air inlet portion connected at its upper end to the fan housing by an annu- The re-enforced Fiberglas housing is of such strucg5 lar outwardly extending shoulder, said fan housing ccmprising a lower curved hood and an upper hood spaced from the lower hood, said lower hood having a curved intermediate portion extending upwardly and outwardly and then downwardly to form a depending end Harige, said lower hood having its opposite end joined to said annular shoulder, said upper hood having a flat circular portion provided with a downwardly and outwardly extending peripheral flange spaced from the flange on the lower hood to form a discharge passage therebetween, means `t'or spacing the lower hood from the upper hood, said motor housing including means for absorbing sound and reducing motor noise, said last named means comprising a porous and rough non-reflecting inner Wall surface of Fiberglas material adjacent said motor, the discharge passage formed by said upper and lower hoods having smooth surfaces of Fiberglas material to facilitate the discharge of air therethrough, said motor housing terminating at a point substantially opposed to the flat circular portion of said upper hood and being laterally spaced therefrom to provide an air passage into said motor housing, means attaching said motor housing to said `fan housing, said attaching means comprising a vertically extending cylindrical sleeve member positioned in said air passage, said sleeve having a at inwardly projecting anged portion overlapping said hat circular portion, said sleeve being attached to said llat circular portion by the means for spacing said upper and lower hoods.

4. An air exhauster of the class described including a casinf7 comprising sound-absorbing, non-resonant tiberreenforced material, said casing being separated into an upper motor housing having a motor therein and a lower fan housing having a fan therein operable by said motor, said fan housing having a depending venturi air inlet portion connected at its upper end to the fan housing by an annular outwardly extending shoulder, said fan housing comprising a lower curved hood and an upper hood spaced from the lower hood, said lower hood having a curved intermediate portion extending upwardly and outwardly to form an end flange, said lower hood having its opposite end joined to said annular shoulder, said upper hood having a flat top portion provided With a downwardly and outwardly extending peripheral flange spaced from the flange on the lower hood to form a discharge passage therebetween, means for spacing the lower hood from the upper hood, said motor housing including means for absorbing sound and reducing the motor noise, said last named means comprising a porous aad rough non-reecting inner wall surface of fiber-reenforced material adjacent said motor, the discharge passage formed by said upper and lower hoods having smooth surfaces of liber-reenforced material to facilitate the discharge of air therethrough.

References Cited in the file of this patent UNITED STATES PATENTS 2,526,291 Solzman Oct. 17, 1950 2,644,389 Dauphinee July 7, 1953 2,711,682 Dreschel June 28, 1955 2,777,382 Solzman Jan. 15, 1957 2,805,974 Brucker Sept. 10, 1957 2,823,598 Jenn Feb. 18, 1958 FOREGN PATENTS 257,490 Great Britain Sept. 2, 1926 

